What type of air quality issue can carbon monoxide cause?

Carbon monoxide is a colorless, odorless gas that can have significant adverse health effects when inhaled, particularly at higher concentrations. The correct choice highlights two common and immediate symptoms associated with carbon monoxide poisoning: headaches and nausea. These symptoms arise because carbon monoxide interferes with the blood's ability to transport oxygen. When carbon monoxide is inhaled, it binds to hemoglobin in the bloodstream more effectively than oxygen, reducing the overall oxygen supply to vital organs and tissues.

This disruption can result in various health issues, starting with mild symptoms like headaches and nausea. In more severe cases, prolonged exposure can lead to confusion, loss of consciousness, neurological damage, and even death.

Other options such as allergic reactions or chronic respiratory problems are typically linked to other pollutants and are not primarily associated with carbon monoxide exposure. Increased energy consumption is unrelated to health effects but might be a consequence of needing to compensate for a lack of fresh air in enclosed spaces that can also increase carbon monoxide levels.